Annular combustion chamber with hollow air guide vanes with radial gasiform fuel slots for gas turbines



2,592,74$ ANES FOR GAS TURBINES Filed June 11, 1945 1 LOW AIR GUIDE V OLTS M. H. L. SEDILLE WITH RADIAL GASIFORM FUEL SLO ANNULAR COMBUSTIONCHAMBER WITH H April 15, 1952 Patented Apr. 15, 1952 ANNULAR COMBUSTIONCHAMBER, WITH HOLLOW AIR GUIDE VAN ES WITH RADIAL GASIFORM FUEL SLOTSFOR GAS TUR- BINE S Marcel Henri Louis Sdille, Paris, France, assignorto Societe Rateau (Socit Anonyme), Paris, France, a company of France,and Ren Anxionnaz, Paris, France, jointly Application June 11, 1945,Serial No. 598,763 In France February 17, 1944 Section 1, Public Law690, August 8, 1946 Patent expires February 17, 1964 3 Claims.

In gas turbine plants, it is desirable that the combustion of fuel becomplete and effected inside a chamber of smallest possible size.

This latter condition is compulsory for certain applications such asmarine propulsion, traction and aviation. In the case of gaseous orgasified fuels, practice shows that the performance of completecombustion over a minimum path depends on the multiplicity of theContact surfaces between the air and the fuel. A great number ofordinary gas burners satisfying these conditions are known but they showhowever excessive losses of head either for the combustive air or forthe gasiform fuel.

In these known arrangements, in order to achieve a rapid and completecombustion, the diffusion of the gasiform fuel inside the combustive airis furthered either through the different speeds given to the air and tothe gas at the outlet of the burner or through obstacles giving rise toa considerable turbulence of the gaseous mixture thus promoting thedesired diffusion. These methods lead however to important losses ofhead for one of the two flows considered. Now it is known that theselosses of head are particularly detrimental in the case of gas turbineplants and that they reduce by a considerable amount the efficiency ofsuch plants.

The present invention has for its object an arrangement of a combustionchamber and burners adapted in particular for use with gas turbineswhereby the losses in head of the gaseous current are reduced to aminimum and yet an intimate contact is ensured between the gasiform fueland the combustive air.

To this end the flow of gaseous fuel and the flow of combustive air aredivided into thin gaseous alternate sheets, each gaseous fuel sheetlying between two sheets of ombustive air and vice-versa, so as toprovide a contact surface as large as possible between said two fluids.In accordance with the invention, the burners, i. e. the nozzles feedinggaseous fuel sheets have preferably the shape of a narrow slot locatedat the end of a flat pipe the outer surface of which forms a partitiondividing the air stream. Thus an air sheet is produced between every twoconsecutive such pipes, said air sheet being in contact throughout bothits surfaces with two fuel sheets each of which is itself in contactwith two air sheets. A radial arrangement of the burners thus gives riseto radial gas sheets alternately composed of fuel and of air.

According to an embodiment of the invention, the flattened gas feedingpipes are arranged in 2 radial formation. The burners are connected toan annular inlet manifold located outside the combustion chamber andthey are also radially arranged and directed parallel to the axis of thechamber. In this embodiment also, the slots of the burners convenientlynarrow down towards the centre.

The burners may be connected through relatively long pipes havingconveniently a fiat shape to a manifold located at an appropriatedistance from the combustion chambers. Thus means for adjusting thepassage cross-section of the ducts can be fitted up on the portions ofsaid pipes lying outside the combustion chambers.

The flattened pipes arranged radially play the part of stationaryguiding fins for air discharged by the compressor and direct this airparallel to the outlet direction of the gaseous fuel issuing from theburner. Part of the air thus directed is not used immediately for thecombustion but for the cooling of the walls of the combustion chamber.It is only then mixed with the combustion products. The combustionchamber itself may have a cross section which increases along theflowing direction of the gases, so as to avoid the gradual accelerationof the gaseous flow. Let So be the cross-section of the chamber in frontof the nozzles of the burners and To the absolute temperature both ofthe gaseous fuel and of the air at the inlet into said chamber, thecross-section S1 at the outlet of said chamber is preferably such thatif T1 is the absolute temperature of the gaseous products of thecombustion at the outlet, the following equation is satisfied:

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawing forming a part of this application and inwhich like numerals are employed to designate like parts throughout thesame:

Fig. l is a fragmentary axial section of the gasturbine plant takenalong line I-I of Fig. 2;

Figure 2 is a cross-section taken along line II-II of Fig. 1; and

Fig. 3 is a developed section taken along line III-III of Fig. 2.

In the drawing, l8 designates the last movable blading of the axialcompressor; the latter discharges between the fins 4, air which dividesinto primary air (arrows 3) which directly takes part in combustion andsecondary air (arrows 3) which flows between the fins in the portionsthereof which do not lie opposite a fuel gas outlet into the chamber,whereby secondary air is not directly used for combustion. Thestationary distributing fins 6 give the air issuing from the blading 18of the compressor an axial direction; these fins are hollow andconnected to the gaseous fuel inlet manifold 14. Each fin 4 thusconstitutes an elementary burner and the gaseous fuel issues therefromas a thin sheet through an aperture provided in a fraction of thetrailing edge 8. The combustion takes place inside a diverging annularduct [9. The fraction of air delivered by the compressor and forming thesecondary air stream does not enter directly the combustion chamber butflows around it along annular space 8 in the direction of the arrows 3',thus cooling the walls of the chamber; it is finally admixed with thecombustion products by passing through the ports 9 in said chamberwalls. Lastly the axial compressor is generally provided with anequilibrating piston 29 adapted to compensate the axial thrust andcomprising at its periphery a quincunx fluid-tight packing 2 l. The airwhich leaks through this packing is used to advantage for forming acirculation of cool air around the combustion chamber; thus a portion ofthe outer wall II is cooled'and preserved from the high temperaturesprevailing inside the combustion chamber and may bear without anydifliculty the overpressure of the driving gases. Lastly in Figs. 1and3, l2 corresponds to the distributor of the gas turbine and I3designates one of the movable wheels thereof.

In the above forms of the invention, large contact areas between the twoflows of gaseous fuel and combustive air are obtained owing to the thinoutlets. Moreover the burners only offer a minimum resistance to theprincipal flow of combustive air.

In the combustion chamber itself, the amount of heat evolved by thecombustion causes an increase in the volume of the fluids circulatingtherein; if the combustion chamber had a constant passage cross-section,this would result in an increase in speed of the combustion productsleading to a reduction in the pressure of the driving gases andconsequently to a loss of head. To avoid this drawback, the combustionchamber is given, as shown in Fig. 1, an increasing crosssection fromthe inlet towards the outlet.

Let S0 and To be respectively the cross-section of the combustionchamber in the vicinity of the inlet, and the absolute temperature ofthe gases therein, and S1 and T1 be the corresponding values at theoutlet of the combustion chamber. According to the invention, the ratioS0281 between the cross-sections is given a value as nearly equal aspossible to the ratio To:T1 of the absolute temperatures, whereby asubstantially constant flowing velocity of the combustion products is 4ensured up to the outlet of the combustion chamber connected to thedistributor of the gas turbine.

What I claim is:

1. A gas-turbine power plant comprising an annular combustion chamber,an axial-flow compressor for supplying air to said chamber, circularlydistributed, stationary, hollow vanes at the discharge end of saidcompressor, adapted to divide the flow of air issuing therefrom into aplurality of generally radial, spaced layers of air, each of said vaneshaving a generally radial, slotlike passage opening on to saidcombustion chamber, and a feed manifold connected to said hollow vanesand adapted to supply therethrough gaseous fuel to said chamber, wherebya plurality of generally radial, spaced layers of gaseous fuel areformed between successive layers of air.

2. A gas-turbine power plant as claimed in claim 1 wherein thecombustion chamber is disposedinside an annular casing the. walls ofwhich are spaced from the walls of the combustion chamber, thusproviding for annular passages between the walls of the combustionchamber and the walls of the casing, these passages being in 7communication on the one hand with the discharge end of the compressorand on the other hand with the combustion chamber.

3. A gas-turbine power plant as claimed in claim 1 in which thecombustion chamber has a gradually increasing cross-section along thedownstream direction, the ratio between the least and largestcross-sections being substantially equal to the ratio between theabsolute temperatures of the gases before and after combustion.

MARCEL HENRI LOUIS sEDILLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 789,554 Lemale May 9, 1905978,044 Loftus Dec. 6, 1910 1,202,736 Kling et al Oct. 24, 19161,980,266 Goddard Nov. 13, 1934 2,078,956 Lysholm May 4, 1937 2,131,977Schwalbe Oct. 4, 1938 2,138,220 Trumpler Nov. 29, 1938 2,242,767 TraupelMay 20, 1941 2,286,909 Goddard June 16, 1942 2,326,072 Seippel Aug. 3,1943 2,332,866 Muller Oct. 26, 1943 2,397,834 Bowman Apr. 2, 19462,410,450 Kroon Nov. 5, 1946 FOREIGN PATENTS Number Country Date 331,555Great Britain July 4, 1930 336,952 Great Britain Oct. 20, 1930 683,439Germany Nov. 6, 1939 542,528 France May 18, 1922

